Influence of intramolecular hydrogen-bonding on the conformation of 3-deoxy-3-thioureido sugars

✍ Scribed by JoséM. García Fernández; Carmen Ortiz Mellet; JoséL. Jiménez Blanco; José Fuentes; Maria Jesús Diánez; Maria Dolores Estrada; Amparo López-Castro; Simeón Pérez-Garrido

• Publisher: Elsevier Science
• Year: 1996
• Tongue: English
• Weight: 602 KB
• Volume: 286
• Category: Article
• ISSN: 0008-6215
• DOI: 10.1016/0008-6215(96)00039-0

✦ Synopsis

3-Deoxy-3-thioureido derivatives of 1,2:5,6-di-O-isopropylidene-a-D-allofuranose and 1,2:5,6di-O-isopropylidene-a-~glucofuranose were prepared, and their contbrmational properties in chloroform-d solutions were studied by temperature variable ~H NMR spectroscopy. The whole results, which include temperature coefficient data for the exchangeable pseudoamide protons, support that the presence of the sugar NH-C(= S) E-rotamer for D-gluco N,N'-disubstituted derivatives can be essentially ascribed to the existence of an intramolecular hydrogen bond analogous to that characteristic of peptide y-turns.